Charities can add the button to the bottom of posts and stories, and so far about 19 have. Theoretically, it's a handy call to action, greasing the wheels between well-intentioned people with money to spare and actual donors.

After the initial test run, Facebook says other non-profits will be able to have access to the button, when vetted and approved. Unlike previous social giving apps that have leveraged Facebook's platform and were stand alone companies, Facebook isn't taking a cut at all and 100 percent of the proceeds go to the charities.

This is great, right? And just in time for Christmas!

One problem: This is in no way what non-profits have been asking Facebook for. It's the social giving equivalent of getting socks for Christmas. Sure, you may wear them, but it's no shiny new bike.

The gift charities really wanted was an Ad Grants program akin to Google's, where Facebook would give accredited non-profits $10,000 worth of promoted posts monthly. That way, non-profits could get their pages in front of more eyeballs, garnering more supporters.

Non-profits have needed this since Facebook's Edgerank algorithm changed in late September, decreasing branded pages' newsfeed reach to get rid of advertising clutter. The change in the algorithm took non-profits out of the running, right along with for-profit companies.

Since charities don't have the funds to pay for promoted posts the way companies can, non-profits say they suffered disproportionately from the change. Chalk it up to another casualty from relying on the Facebook platform, unintended as it may have been. As one source in the non-profit world told me, "If no one can see the donate button how will that help?"

Also, Facebook will not be giving users' email addresses to said charities when they donate. (Which users may actually love.) That means that all charities get out of the transaction is money, when what would actually be the most useful is the beginning of a connection with the giver.

Besides it not being what non-profits want, there's an open question of whether social giving even works. The promise five or six years ago was that social media would be able to reach so many people, with highly personal stories and friend-to-friend recommendations to give. The hope was to flip non-profit economics on their head: Instead of having to land a whale because of the costs entailed in finding donors, social media could bring in a wave of micro-donors more cost effectively, ala President Obama's election campaign.

But with some exceptions like Charity:Water, that's mostly failed. Time and time again we've seen social giving applications flounder, even with unfair advantages from social platforms. Consider Sean Parker's and Joe Green's highly publicized app Causes. Both are close friends with Mark Zuckerberg, and the app got special treatment from the Platform. Even still, it struggled and wound up moving off Facebook after its traffic declined.

Facebook has struggled to even make for-profit, selfish gifting work, shuttering its physical Gifts program after barely half a year.

It's possible that social gifting is still some sort of Holy Grail done right, and that these apps just came before their time. John Trybus, of consulting firm Waggener Edstrom that penned a report on how social media drives support for causes, believes that now the circumstances are right for social giving.

We see a lot of non-profits have dedicated social media communication managers. So non-profits are getting more and more sophisticated from their side of things and I think Facebook is also getting more sophisticated, so the two are meeting, as well as supporters. They're understanding that social media isn't something to be afraid of, or something where they can't give their credit card information online.

The Facebook donate option certainly cuts down the additional steps someone needs to take to give to a charity, whether mailing in a check or going to the website. Theoretically, that leads to higher conversion rates and more money for the non-profits. Lana Volftsun of the One Percent Foundation, for one, was excited about the move.She called it, "a great opportunity for Facebook to play a larger role in peer to peer fundraising and an exciting option for nonprofits who typically use fundraising platforms that take 5-10 percent in fees."

It's possible that the social media opportunity for non-profits is more nuanced than apps like Causes originally envisioned. Rather than closing donors, the social media presence for non profits should be focused on community building. Non-profits run the risk of turning people off to their organizations if every post they make looks like they're asking for handouts. Instead, it may be an Upworthy-like opportunity to communicate, evangelize to a base, and get the story out there.

Beth Kanter, a non-profit fundraiser and co-author of two books on the topic, advises against shoving a Donate butting in front of people just because non-profits can. "There's a saying don't build your network before you need it," Kanter says. "All good fundraisers know that [the donation moment] is just the beginning of a relationship."